/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package com.system.distribute.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.FileRegion;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.util.CharsetUtil;

import java.io.File;
import java.io.FileInputStream;

/**
 * Server that accept the path of a file an echo back its content.
 */
public class FileServer {

    private final int port;

    public FileServer(int port) {
        this.port = port;
    }

    public void run() throws Exception {
        // Configure the server.
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .option(ChannelOption.SO_BACKLOG, 100)
             .handler(new LoggingHandler(LogLevel.INFO))
             .childHandler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ch.pipeline().addLast(
                             new StringEncoder(CharsetUtil.UTF_8),
                             new LineBasedFrameDecoder(8192),
                             new StringDecoder(CharsetUtil.UTF_8),
                             new FileHandler());
                 }
             });

            // Start the server.
            ChannelFuture f = b.bind(port).sync();

            // Wait until the server socket is closed.
            f.channel().closeFuture().sync();
        } finally {
            // Shut down all event loops to terminate all threads.
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = Integer.parseInt(args[0]);
        } else {
            port = 8080;
        }
        new FileServer(port).run();
    }

    private static final class FileHandler extends SimpleChannelInboundHandler<String> {
       

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
            cause.printStackTrace();
            ctx.close();
        }

		@Override
		protected void channelRead0(ChannelHandlerContext ctx, String msg)
				throws Exception {
			 File file = new File(msg);
	            if (file.exists()) {
	                if (!file.isFile()) {
	                    ctx.writeAndFlush("Not a file: " + file + '\n');
	                    return;
	                }
	                ctx.write(file + " " + file.length() + '\n');
	                FileInputStream fis = new FileInputStream(file);
	                FileRegion region = new DefaultFileRegion(fis.getChannel(), 0, file.length());
	                ctx.write(region);
	                ctx.writeAndFlush("\n");
	                fis.close();
	            } else {
	                ctx.writeAndFlush("File not found: " + file + '\n');
	            }
			
		}
    }
}
